Electric switch



NOV. 15, 1932. w A ATWOOD 1,887,535

ELECTRIC SWITCH Filed March 28, 1930 IIIIIII m log His Attorney.

Patented Nov. 15, 1932 UNITED STATES PATENT OFFIE WINFIELD A. .ATWOOD, F YEADON, PENNSYLVANIA, ASSIGNOB T0 GENERAL ELECTRIC COMPANY, A CORPORATION OF NEW YORK ELECTRIC SWITCH Application filed March 28, 1930. Serial No. 439,837.

My invention relates to improvements in electric switches and more particularly circuit breakers and has for an object to provide an improved circuit breaker construc- Uircuit breaker requirements, as to number of poles, vary over a relatively wide range, for example from single-pole circuit breakers to at least five-pole circuit breakers.

When a separate circuit breaker is built for each pole number requirement, the number of parts and different circuit breakers to be manufactured and also carried in stock in order to give efiicient service is large. This naturally tends to increase the cost of the product and ultimately the cost of electricity to the consumer. An object of my invention is to avoid these diflieu'lties. Accordingly, I provide a flexible circuit breaker construction embodying a minimum number of parts which can be assembled to form circuit breakers with any desired number of poles whereby to obtain the economies of simplitied manufacture and distribution. Other objects of my invention will appear hereinafter.

My invention will be better understood from the following description when considered in connection with the accompanying drawing and its scope will be pointed out in the appended claims.

In the accompanying drawing, Fig. 1 illustrates in perspective a three-pole circuit breaker embodying my invention; Figs. 2 and 3 illustrate partial front Views of single and double-pole circuit breakers embodying my invention; and Figs. 4:, 5 and 6 illustrate a trip-free mechanism in the closed, tripped or open, and resetting positions respectively, which may be used in circuit breakers embodying my invention.

The illustrated embodiment of my invention includes a plurality of substantially ident cal single-pole circuit breaker units, indicated generally as 10, which are mounted on a suitable base or panel 11 and which are arranged to be actuated to the circuit closing position by a single toggle mechanism 12 of the trip-free type.

Each pole unit includes lower and upper conducting studs 13 and 14 respectively, the latter forming the main stationary contact of the circuit breaker, a movable contact 15, a carrier or brush lever 16 therefor, and a bracket 17 on which the carrier is pivoted at 18. Each pole unit may also include means responsive to abnormal conditions in the circuit through the unit for eliecting the opening of the circuit breaker. As shown, this means includes a trip coil 19 connected in series with the contacts 1 1, 15 and arranged to actuate a trip pin 20 whereby to collapse the toggle mechanism 12 as will hereinafter appear. In order that the movable contacts 15 may be actuated simultaneously in the circuit opening and closing movements, they are pivotally mounted through their carriers 16 on suitable inter-connecting means such as a common rod 21. This rod may be insulated from all but one of the carriers by any suitable means, for example bakelite thimbles 22, the thimbles being provided with collars to prevent lateral movement of the carriers. For simplicity in construction, a bushing sleeve 23 of metal may be provided between the collars. In this way a rod of uniform size throughout its length may be used, no matter what the number of pole units.

The single toggle operating mechanism 12 includes pivotally interconnected links 24 and 25, an operating member 26, latching means for interlocking the link 25 and the member 26, and latching means for holding the member 26 in the circuit closing position whereby to maintain the toggle 24, 25 rigid in an underset condition when the link 25 and the member26 are interlocked. The toggle mechanism 12 is pivotally mounted together with its latching means at 9 on a supporting member suitably secured to the base 11 and having side arms or brackets 27, one on each .side of a pole unit and preferably symmetrically positioned with respect to the pole units to provide a more uniform distribution of the load on the rod 21 as well as for the sake of appearance.

The latching means for interlocking the link 25 and the operating member 26 includes two cooperating latches 28 and 29 which are to latching position by a spring 32. The

latch 28 may be provided with a steel insert 33 which engages a cooperating insert 34 on the link 25, both inserts having hardened engaging surfaces. The latch 29 engages the latch 28 through suitable means such as a roller 35 pivoted thereon and is provided with a tripping arm 36.

The latching means for holding the circuit breaker closed when the link 25 and the operating member 26 are interlocked includes a latch 37 pivotally mounted on the arms 27 at 38 and arranged to engage a roller on the pivot 31 of the latch 29. Clockwise movement of the latch 37 is limited by a stop 39 on the arms 27. This stop also serves to limit the circuit breaker opening movement through a buffer 40 on the carrier 16.

In order that the latching mechanism may be tripped in response to an abnormal condition in the circuit through any one of the pole units, I provide a tripping bar 41. This extends across all the pole units provided with tripping means and is provided with lugs 42 in the path of movement of the trip pins 20. The tripping bar 41 also carries a tripping lug 43 which extends into the path of movement of the latch arm 36 so that when the tripping bar 41 is actuated counterclockwise by the upward movement of a trip pin 20, the latch 29 is released from the roller 35 to permit the opening of the circuit breaker. The latch 37 is released from its roller on the pivot 31 when the carrier 16, in the circuit opening movement, engages the tail of the latch and rotates it counter-clockwise as shown in Fig. 5.

Fig. 4 shows the parts of the toggle operating mechanism positioned as when the circuit breaker is closed. When the latch 29 is released by the tripping lug 43, the latch 28 is free to move counter-clockwise and the latching insert 34 on the operating member 26 moves free from the latching insert 34 on the link 25 under the opening bias of the contacts 15, the latching member 28 being pressed downwardly by and riding along the curved edge 44 of the link 25. The parts are now positioned as shown in Fig. 5. In order to reclose the circuit breaker, the operating member 26 is turned clockwise from the position shown in Fig. 5 to the position shown in Fig. 6. When the insert 33 reengages the insert 34, the latch 28 moves clockwise sufiiciently under the bias of the spring 32 to be engaged by the latch 29 at the roller 35, the latch'29 being biased counter-clockwise by the spring 32. The link 25 and the member 26 are now interlocked and clockwise movement of the member 26 closes the circuit breaker which is held closed by the latch 37 engaging the roller on the pivot 31 unless the circuit through a pole is abnormal.

A tripping knob, not shown, may be mounted on the tripping bar 41 for tripping the breaker manually, as is well known to the art.

In order to illustrate the flexibility of circuit breaker construction embodying my invention, reference is now to be had to Figs. 2 and 3 which illustrate single and doublepole circuit breakers respectively embodying my unit construction. It will be observed in Fig. 2 that a single-pole unit and a single operating mechanism are used to form a single-pole circuit breaker. In Fig. 3 two single-pole unitsare shown with a single toggle operating mechanism. It will be apparent from Fig. 3 that by merely using a longer rod 21 two pole units can be added, one to the right and one to the left of the pole units shown constitute a four-pole breaker. Likewise, with reference to Fig. 1, by using a longer rod 21 two pole units can be added, one to the right and one to the left of the extreme pole units shown to constitute a fivepole breaker. Thus with circuit breakers embodying my unit construction, the flexibility of assembly for different pole number requirements with the minimum number of parts and particularly the minimum number of toggle mechanisms is apparent.

While I have shown and described my invention in considerable detail, I do not desire to be limited to the exact arrangements shown, but seek to cover in the appended claims all those modifications that fall within the true spirit and scope of my invention.

What I claim as new and desire to secure by Letters Patent of the United States is:

1. A multiple-unit circuit breaker construction including a plurality of single-pole units and a single toggle operating mechanism, each pole unit including a movable contact biased to circuit opening position, fault responsive means for collapsing the toggle of said mechanism on the occurrence of an abnormal condition in the circuit through a pole unit, and means for interconnecting the contacts and said mechanism including a rod on which said contacts are mounted the toggle of said mechanism being directly connected to said rod.

2. A multiple-unit circuit breaker construction including a plurality of single-pole units and a single trip-free toggle operating mechanism, each pole unit including a movable contact biased to circuit-opening position and certain of said pole units including a trip coil for collapsing the toggle of said mechanism on the occurrence of current above a predetermined value in the circuit through said certain pole units and means for interconnecting the contacts and said mechanism including a rod on which said contacts are pivotally mounted the toggle of said mechanism being directly connected to said rod substantially symmetrically with respect to said contacts.

3. A multiple-unit circuit breaker construction including a plurality of singlepole units assembled with a single trip-free operating mechanism to form a multi-polar circuit breaker, each pole unit including a movable contact biased to circuit opening position, fault responsive means for directly tripping said mechanism on the occurrence of an abnormal condition in the circuit through a pole unit, and a rod supporting the movable contacts of the pole units and interconnecting the contacts with said mechanism, the mechanism being directly connected to the rod substantially symmetrically with respect to the pole units.

4. A multiple-unit circuit breaker construction including a plurality of single-pole units and a single toggle mechanism for closing the circuit breaker, each pole unit including a movable contact biased to circuit opening position and a trip coil responsive to abnormal conditions in the circuit through the pole unit, a common tripping member for collapsing the toggle mechanism arranged for actuation by each of the trip coils and means for interconnecting the contacts and the toggle of said mechanism ineluding a rod on which said contacts are mounted the toggle of said mechanism being directly connected to said rod.

5. A multiple-unit circuit breaker construction including a plurality of single-pole units, each pole unit including a movable contact biased to the circuit opening position, a single toggle mechanism for actuating the pole unit contacts to the circuit closing position,and means for interconnecting the contacts and the toggle of said mechanism including a rod on which said contacts are pivotally mounted, the toggle of said mechanism being directly connected to said rod.

6. A multiple-unit circuit breaker construction including a plurality of single-pole units and a single toggle operating mechanism, each pole unit including a movable contact biased to circuit opening position, means for collapsing the toggle of said mechanism on the occurrence of an abnormal condition in the circuit through any pole unit, and means for interconnecting the contacts and said mechanism including a member on which said contacts are mounted, the toggle of said mechanism being directly connected to said member.

WINFIELD A. ATWOOD 

